Pick-up device



A. R. STAHL PICK-UP DEVICE Filed Nov. 18, 1953 Feb. 18, 1958 InVentOT' Alfred R. Stahl,

United States Patent PICK-UP DEVICE Alfred R. Stahl, Garnet Lake, N. Y., assignor to General Electric Company, a corporation of New York Application November 18, 1953, Serial No. 392,901

12 Claims. (Cl. 271-43) My invention relates to automatic machinery and pertains more particularly to a novel arrangement for automatically picking up individual elements seriatim from a stack of such elements, and maintaining the stack at a substantially constant level.

in some automatic machinery such as that employed in electron tube manufacture it is desirable to provide an arrangement for picking up elements such as waferlike insulators seriatim from a stack of such elements. Additionally, in such an arrangement it is desirable to include means for maintaining the top of the stack at a substantially constant level and for feeding elements to the stack to sustain it. If the stacked elements are not of uniform thickness it is not possible to maintain a constant level simply by utilizing a steady feeding arrangernent.

Accordingly, a primary object of my invention is to provide a new and improved pick-up device.

Another object of my invention is to provide, in a device for picking up elements, of varying thicknesses from a stack thereof, a new and improved arrangement for maintaining the stack at a substantially constant level.

Another object of my invention is to provide, in a device for picking elements up from a stack thereof, a new and improved arrangement for feeding elements to the stack to sustain it.

Still another object of. my invention is to provide a device for picking up elements from a stack thereof including arrangements for maintaining the stack at a substantially constant level and feeding elements to the stack for sustaining it, which is simple in construction, inexpensive to manufacture, reliable and which during operation, requires a minimum of attention from an operator.

Further objects and advantages of my invention will becomev apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in the claims arinexedto and'forming part of this specification.

In carrying out the objects of my invention I provide a. device including a reciprocating pick-up member arranged for repeatedly engaging the top of a stack of elements for picking up the elements seriatim. Cooperating with the stack is means for raising the stack and feeding elements to the bottom thereof. Other means is provided which is operative in accordance with the extent of reciprocal movement of the pick-up member and is effective when the level of the stack stands at a predetermined minimum level and the reciprocal movement is of a predetermined magnitude for actuating the means for raising the stackand feeding the elements to the bottom thereof. For a better understanding of my invention reference may be had to the accompanying drawing in which:

. .Eig. 1 is a front elevational view, partially broken away, illustrating apreferred embodiment of my invention; ig. 1-A is a schematic plan view illustrating the manner in which the pick-up member may be moved to various'operating stations 1 a "ice Fig. 2 is a fragmentary front elevational view illustrating the device in one operative position; and

Fig. 3 is a similar view illustrating the relative disposition of parts when the device is in another operative position.

Referring to Fig. 1, there is shown a preferred embodiment of my invention which comprises a pick-up member generally designated 1, which, in turn, comprises a horizontal arm 2 secured intermediate its ends on a sleeve 3. Carried on each extremity of the arm 2 (only one of which is shown) is a pendant rod 4 to which is secured a pick-up tip or button 5.

The sleeve 3 is secured to a wheel-like member 6. The sleeve 3 and the member 6 are both fitted rotatably and slidably on a vertical spindle 7 suitably secured in a stationary base 8. Formed in the member 6 is a peripheral groove 9 for receiving a pair of opposing studs 10 (only one of. which is shown) secured in the tines 11 of a bifurcated lever 12. The bifurcated lever 12 is secured at its extremity on a rock shaft 13 journaled in a stationary frame member 14. By suitable means (not shown) the shaft 13 is arranged to be oscillated or rocked a predetermined amount about its longitudinal axis, and rocking of the shaft in this manner is effective for oscillating the bifurcated lever 12 in a vertical plane. Through the studs 10 and the groove 9 in the member 6 this movement of the bifurcated lever causes reciprocation on the spindle 7 of the member 6, the sleeve 3 and the pick-up member l carried by the sleeve.

In addition to reciprocating, the pick-up member 1 is arranged to rotate clockwise on the spindle 7 in the manner indicated in Fig. l-A. This is accomplished with the aid of a pin 15 which extends slidably through a suitable aperture 16 in the horizontal arm 2 just outwardly of the spindle 7. The pin 15 is secured in the extremity of a lever 17 rotatably fitted on the spindle 7. By suitable means (not shown) the lever 7 and, therefore, the pick-up arm 2 is arranged for being intermittently positioned in a plurality of radial positions, such as those indicated by A, B and C in Fig. l-A,in timed relationship with the reciprocation of the pick-up member. Thusthe pick-up member is caused to reciprocate at every radial position thereof.

When the pick-up member is in position A a pick-up tip 5 thereon is disposed directly above a stack generally designated 18 of wafer-like elements 19. During reciprocation of the pick-up member in this position it, and more specifically the pick-up tip 5 thereof, engages the top of the stack 18 or the uppermost of the elements 19 in the stack for picking it up from the stack. This is preferably accomplished by coating the tip 5 with a substance which will cause the element to adhere to it when the pick-up member moves upwardly. By way of example of how the tip can be coated with an adhesive material, the tip can be dipped into oil or any other suitably adhesive'substance at one of the radial positions of the pick-up member in advance of the one above the stack, such as position C. At another radial position, beyond the one corresponding to the stack and before the dipping position, such as position B, the pick-up memv ber can be employed for depositing the element picked up at another operating station. Thus, repeated recipof the spider can be so controlled as to provide engage 3 ment of each of thetips with the top of the stack during each revolution of the pick-up member.

The stack 18 is contained in one of a pair of spaced apart vertical portions "20 of a -U-shaped channel 21 suitably formedin-a:channelblock 22 and including an arcuate portion 23 connecting'the lower ends of the verticalportionsZO. As seen in Fig. 1 the arcuate portion 23 of the channel is adapted for containing elements to be fed to the bottom of the stack-18 for sustaining it and the other vertical portion 20 of the channel is adapted for receiving and containing elements for being gravity-fed to the arcuate portion. As also seen in Fig. l, the block 22 further includes a wheel housing 24 which communicates with the channel 21. Provided in the housing 24 and'secured on ashaft 25 journaled be tween the front and'rear walls of the block 22 is a wheel 26. The periphery of the wheel 26 is surfaced with a material such as rubber in the manner indicated at 27 in 'Fig. 1 for rendering'it a friction wheel. The communication between the arcuate portion 23 of thechannel and the wheel housing 24 exposes lateral portions of the elements in the channel 21 to the friction surface of the wheel. As a result, the elements are frictionally engaged by the wheel and actuated in the channel 21 when the wheel is rotated. The wheel 26 is adapted for being actuated or-rotated counter-clockwise in the drawing thereby to lift thestack 18 comprising the elements 19 contained in the right hand vertical portion 20 of the channel for raising the level of the stack and to feed elements from the arcuate portion '23 of the channel to the bottom of the stack.

- When the elements are fed to the stack from the arcuate portion of the channel in the just described manner a void is momentarily caused in the channel between the elements in the arcuate portion and those in the other 'or left hand vertical portion. This, however, is substantially immediately lined by elements gravity-fed to the arcuate portion from' the left hand vertical portion of the channel. It will be seen, of course, that the left hand vertical portion of the channel. may be refilled with elements as required and that an open-end vertical slot 28 facilitatesdetermination by an operator when refilling is required.

Ratchet means is provided for actuating 'or rotating the wheel 26 to lift the stack 18 and thereby raising the level thereof. This ratchetjmeans is operative in accordance with the extent of reciprocal movement of the pick-up member 1 and is effective when the top of the stack of elements stands at a predetermined minimum level'indicated by 29 in Fig. 3 and the reciprocal movement is of a predetermined magnitude. The ratchet means includes a ratchet wheel 30 secured on an externally extending portion of the shaft 25. Provided for cooperating with the ratchet wheel 30 1s 'a pawl 31 .pivotally secured on the lower end of a slide member '32 suitably arranged for vertical sliding movement on the front side of the'block 22. By means of a pin and'slot connectionjgenerally designated 33, the upper end of the'slide member 32 is so connected to the bifurcated lever '12 adjacent the rock shaft 13 that movement of the rock shaft to reciprocate the pick-up member 1 results in a proportionately smaller vertical movement of the slide member.

When the stack 18 stands between a predetermined maximum level indicated by 34 in Figs. 2 and 3 and the predetermined minimum level 29 in Fig. 3 the downward extent of reciprocal movement of the pick-up member in'engaging the top ofthe stack for picking off the uppermost element'therein is limited so as to result in only slight or limited vertical movement of the'slide-rnember 32. This limited vertical movement of the slide member causes the pawl 31-to move-from the dot and dash :line position to the solid line position of F g. This is .less than a toothspace .onithe ratchetwheel 30, and, therefore, during the upward or Ietunl mov ent of the pick-up member-and =slide member the -pawlis inelfective for rotating theratchet wheel and simply returns to the dot and dash line position. This condition continues until after seriatim pick-up of the elements from the stack the height of the stack is reduced to the predetermined minimum 29 of Fig. 3.

When the stack stands at the predetermined minimum level 29 the downward extent of the reciprocal movement of the pick-up member when it engages the top of the stack is of such magnitude that the vertical downward movement of the slide member 32 is greater than the limited movement referred to above. This causes the pawl 31 to be moved from the dot and dash line position to the solid line position of Fig. 3, or a whole tooth space. On the return or upward movement of the pick-up member and slide member the pawl is then operative for actuating or rotating the ratchet and friction wheel counterclockwise one tooth space whereby the stack is lifted for raising the level thereof to the predetermined maximum level 34 aud'elements are fed to the bottom of the stack for sustaining it. Additionally, elements are then gravity-fed from the left hand vertical portion of the channel to the arcuate portion.

It will be seen that the distance between the predetermined maximum level 34 and the predetermined minimum level 29 can be varied to any dimensions by an appropriate selection of pitch on the ratchet wheel 25.

While I have shown and described a specific embodiment of my invention, I do not desire my invention to be limited to the particular form shown and described and I intend by the appended claims to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A device for picking up individual elements seriatim from a stack of such elements comprising; a reciprocating pick-up member arranged for repeatedly engaging the top element of said stack to pick up such top element for removing the same, means for lifting said stack to raise the level thereof, and means operative in accordance with the extent of reciprocal movement of said pick-up member and effective when the level of said stack stands at a predetermined minimum level and the reciprocal movement of said member is of a predetermined magnitude for actuating said lifting means.

2. A device for picking up individual elements seriatim from a stack of such elements comprising; a reciprocating member arranged for repeatedly engaging the top of said stack, means for lifting said stack to raise the level thereof and for feeding elements to the bottom of said stack, and means operative in accordance with the extent of reciprocal movement of said member and effeetive when the level of said stack stands at a predetermined minimum level and j the reciprocal movement jofsaid member is of a predetermined magnitudeffor actuating said lifting and feeding means.

3. A devicefor picking up individualelements-seriatim from a stack of-such elements comprising;'a reciprocating pick-up member arranged for 'rep'eatedlyengaging thetop element of said stack to pick up such top element for removingthe same, means forlifting saidistack to raise the level thereof and ratchet jmeans operative in accordance with the extent of reciprocal movement 'of said pick-up member-and effective-when the level o'fsaid stack stands at a predetermined minimum level and the reciprocal movement 'of said pick-up member is of a predetermined magnitude for actuating said lifting means.

4. A device for picking up individual elements seriatim from a stack, of suchelements comprising; a reciprocating pick-up member arranged for repeatedly engaging the top of said stack,-lifting and feeding means for lifti ugtsaid stack to raise'the-levelthereof and forfeedingelements to the bottomof said stack,;and ratchet. means operative in accordance with the extent of reciprocal movement of said pick-up member and effective when the level of said stack stands at a predetermined minimum level and the reciprocal movement of said pick-up member is of a predetermined magnitude for actuating said lifting and feeding means.

5. A device for picking up individual elements seriatim from a stack of such elements comprising; a reciprocating pick-up member arranged for repeatedly engaging the top of said stack, a friction member engaging portions of elements in said stack for lifting said stack thereby to raise the level thereof, and ratchet means operative in accordance with the extent of reciprocal movement of said pick-up member and effective When the level of said stack stands at a predetermined minimum level and the reciprocal movement of said pick-up member is of a predetermined magnitude for actuating said friction member.

6. A device for picking up individual elements seriatim from a stack of such elements comprising; a reciprocating pick-up member arranged for repeatedly engaging the top of said stack, means including a channel having a vertical portion for containing said stack, a friction wheel engaging lateral portions of elements in said stack for lifting said stack in said channel to raise the level thereof, and ratchet means operative in accordance with the extent of reciprocal movement of said pick-up member and effective when the level of said stack stands at a predetermined minimum level and the reciprocal movement of said pick-up member is of a predetermined magnitude for rotating said wheel.

7. A device for picking up individual element seriatim from a stack of such elements comprising; a reciprocating pick-up member arranged for repeatedly engaging the top of said stack, means including a channel having a vertical portion for containing said stack, said channel further having an arcuate portion for containing elements to be fed to the bottom of said stack, a friction wheel engaging lateral portions of elements in said charinel for lifting said stack to raise the level thereof and for feeding said elements in said arcuate portion of said channel to the bottom of said stack, and ratchet means operative in accordance with the extent of reciprocal movement of said pick-up member and effective when the level of said stack stands at a predetermined minimum level and the reciprocal movement of said pick-up member is of a predetermined magnitude for rotating said wheel.

8. A device for picking up individual elements seriatim from a stack of such elements comprising; a reciprocating pick-up member arranged for repeatedly engaging the top of said stack, means including a channel having a. pair of spaced apart vertical portions and an arcuate portion connecting the lower ends of said vertical portions, one of said vertical portions being adapted for containing said stack of elements, said arcuate portion being adapted for containing elements to be fed to the bottom of said stack, the other of said vertical portions being adapted for holding a supply of elements, a friction Wheel engaging lateral portions of elements in said channel for lifting said stack to raise the level thereof and for feeding said elements in said arcuate portion of said channel to the bottom of said stack, said arcuate portion having elements gravity-fed thereto from said other vertical portion of said channel, and ratchet means operative in accordance with the extent of reciprocal movement of said pick-up member and effective when the level of said stack stands at a predetermined minimum level and the reciprocal movement of said pick-up member is of a predetermined magnitude for rotating said friction wheel.

9. A device for picking up individual elements seriatim 6 from a stack of such elements comprising; a reciprocating pick-up member arranged for repeatedly engaging the top of said stack, means including a channel having a pair of spaced apart vertical portions and an arcuate portion connecting the lower ends of said vertical portions, one of said vertical portions being adapted for containing said stack of elements, said arcuate portion being adapted for containing elements to be fed to the bottom of said stack, the other of said vertical portions being adapted for holding a supply of said elements, a friction wheel engaging lateral portions of elements in said channel for lifting said stack to raise the level thereof and for feeding said elements in said arcuate portion of said channel to the bottom of said stack, said arcuate portion having elements gravity-fed thereto from said other vertical portion of said channel, a ratchet wheel for driving said friction wheel, and a pawl cooperating with said ratchet wheel, said pawl being arranged to move in accordance with the extent of reciprocal movement of said pick-up member, said pawl moving a tooth space on said ratchet wheel only when the level of said stack stands at a predetermined minimum level for rotating said ratchet wheel and said friction wheel.

10. In a device for feeding elements from the top of a stack of such elements, a reciprocating member arranged for repeatedly engaging the top of said stack, means for lifting said stack to raise the level thereof including means adapted for engaging the edges of elements in said stack and being upwardly actuated, and means operative in accordance with the extent of reciprocal movement of said member and effective only when the level of said stack stands at a predetermined minimum level and the reciprocal movement of said member is of a predetermined magnitude for actuating said means for lifting said stack.

11. A device for picking up individual elements seriatim from a stack of such elements comprising; a reciprocating pick-up member arranged for repeatedly engaging the top of said stack, means including a channel having a vertical portion for containing said stack, said channel further having an arcuate portion for containing elements to be fed to the bottom of said stack, a friction wheel disposed adjacent said arcuate portion of said channel and engaging the edges of elements therein, said wheel being rotatable for lifting said stack to raise the level thereof and for feeding said elements in said arcuate portion of said channel to the bottom of said stack, and means operative in accordance with the extent of said reciprocal movement of said member and effective only when the level of said stack stands at a predetermined minimum level and the reciprocal movement of said pick-up member is of a predetermined magnitude for rotating said wheel.

12. A device for picking up individual elements seriatim from a stack of such elements comprising a reciprocating member arranged for repeatedly engaging the top element of said stack to pick up such top element for removing the same, means for lifting said stack to raise the level thereof and for feeding elements to the bottom of said stack, and means operative when the level of said stack reaches a predetermined minimum level for actuating said lifting and feeding means.

References Cited in the file of this patent UNITED STATES PATENTS 2,018,373 Maxwell Oct. 22, 1935 2,067,380 Cross Jan. 12, 1937 2,355,078 Osborn Nov. 23, 1943 2,530,670 Von Hofe Nov. 21, 1950 

